2000 ford focus headlights flashing
 

The wife drives down the road and the dash light and headlights flash all the time. It sort of messes with the idol a bit. the lights never go out. they go dim then go bright, at night other driver dont know what the think. Is this a common probem? I dont think its wiring. high idol or low idol at a stop light and even 60 mph. does it all the time. anybody can help.